For some decades it has been recognized that a significant number of children are persistently hyperactive and have an attention span so short as to be disabling in school and in many personal relationships. Such children in earlier times would no doubt have been dismissed as incorrigible and punished or even confined in an institution. More recently, however, it was realized that these children cannot control their hyperactivity and inattention, and the medical professions began to try to help them. Methylphenidate (Ritalin.TM.)has been used for some time to treat such children and it often significantly improves their ability to function and coexist with other people at school and at home. However, the drug has the disadvantages of requiring several doses per day, and producing a rebound effect as the effect of each dose fades away. Further, the drug causes sleeplessness and lack of appetite in some patients. Methylphenidate has both noradrenergic and dopaminergic activities.
Imipramine, desipramine, nortriptyline, amitriptyline and clomipramine are also used in some cases of attention-deficit/hyperactivity disorder (ADHD). Those tricyclic drugs, however, have a number of physiological mechanisms and, as a class, tend to produce a number of side effects and require careful supervision and dose titration.
In the last decade, psychiatrists have realized that ADHD is not only a disorder of childhood, but often continues in the adult. It is obvious that hyperactivity and short attention span cause grave disruption in an adult's life, but it is only recently that such patients have been able to obtain any treatment.
The need for a safe and convenient treatment for ADHD, applicable to both children and adults and without the disadvantages possessed by methylphenidate continues to be a concern of the psychiatric profession.